Network printer driver needs update

Hi, We have a 2 node server 2003 clustered file/print server. We have 4 groups of users of approx 50 members each with windows 7 pro laptops that had the printers installed for them last fall. This past monday we had a failover of the print cluster to the secondary node and then noticed that one of those user groups laptops would not print any more to the one network printer they point to. When highlighting the printer on the client's machine, the status displays printer needs updated driver, or something similar to that. We did logon as a domain admin and re-installed the printer from the server which brought down the driver again and now all are printing again, but why would a failover cause 1 of the groups of laptops require the driver be reinstalled? at least 2 of the printers are the same type and model.

Thanks for any suggestions!